class Student:
    def __init__(self, id, name='', age='', gender='', grade='' , email='', phone='', address='', enrollment_date=''):
        self.id = id
        self.name = name
        self.age = age
        self.gender = gender
        self.grade = grade
        self.email = email
        self.phone = phone
        self.address = address
        self.enrollment_date = enrollment_date.strftime('%Y-%m-%d')

    def to_dict(self):
        return {
            'id': self.id,
            'name': self.name,
            'age': self.age,
            'gender': self.gender,
            'grade': self.grade,
            'email': self.email,
            'phone': self.phone,
            'address': self.address,
            'enrollment_date': self.enrollment_date
        }

    def __str__(self):
        return f"Student ID: {self.id}, Name: {self.name}, Age: {self.age}, Grade: {self.grade}, Gender: {self.gender}, Email: {self.email}, Phone: {self.phone}, Address: {self.address}, Enrollment Date: {self.enrollment_date}"
